Common origin of life as proof of evolution

This is my first post here so excuse me if I'm in the wrong place or proposing a topic that's already been beaten to death by others.

All (or most) living things share the same genetic apparatus & codes, such as RNA, DNA, chromosomes, ribosomes, amino acids, genetic enzymes, etc. Examples of slightly different genetic codes exist but there are a number of possible explanations for their existence, none of which invoke the agency of the supernatural.

All (or most) living things share the same metabolic systems, with some explanable variations. For example, organisms exist with 'reverse Krebs cycles' as compared to most creatures have 'forward' Krebs cycles.

The natural origin of life not only cannot be dismissed, it may have likely happened several times, with some lines dying out while others served to exchange genetic information with the one(s) that did survive before dying out. Evolution via natural selection has functioned from the earliest times.

My thesis is as follows: the common nature of these aspects of life on a molecular level is very strong evidence that they only originated once & evolved as life did. We do not see the existence of entirely dissimilar genetic or metabolic systems that would illustrate entirely separate origins.

Let me leave my argument here & see where it goes.

Jack

Edited by John Sullivan, : Revise grammar

Thread copied here from the Common origin of life as proof of evolution thread in the Proposed New Topics forum.

In science we don't do "proof". Proof is for alcohol and maths.

In science we do evidence.

the common nature of these aspects of life on a molecular level is very strong evidence that they only originated once

Probably. A cookie cutter god using the same wiring scheme for her various creations fits this molecular system quite well.

One might expect that if a natural origin were all there was then, on a rock this size, the molecular processes might have produced several different schemes for an initial replicant and thus different molecular schemes in the evolved products.

Welcome to EvC, Jack. Glad to have you.

JohnS writes: ... the common nature of these aspects of life on a molecular level is very strong evidence that they only originated once

Welcome home. Pull up a stump and set a spell.

Kinda, sorta, maybe.

There is another equally likely possibility is that what we see today is the surviving, more successful original line. Just as the more successful at reproducing in any given environment tends to dominate that environment it's possible that in the beginning several entirely different formats originated, but the one we see today was simply the most adaptable within the original environment and within the evolving environment.

Edited by jar, : No reason given.

Hello John Sullivan,

My thesis is as follows: the common nature of these aspects of life on a molecular level is very strong evidence that they only originated once & evolved as life did. We do not see the existence of entirely dissimilar genetic or metabolic systems that would illustrate entirely separate origins.

Do a search on "RNA World" ... it appears the best explanation to date is that RNA evolved chemically and out-competed other systems for self-replicating molecules, but then DNA evolved chemically and took over.

Some old threads of mine on this topic are Panspermic Pre-Biotic Molecules - Life's Building Blocks (Part I) and Self-Replicating Molecules - Life's Building Blocks (Part II) -- they are both old and there has likely been much discovered since.

... as proof of ...

Do you prove theories in chemistry? I know it works in math, but generally in science it seems we develop theories as the best known explanations rather than prove them.

Can we ever prove that life evolved chemically from molecules or are we limited to developing the best explanation based on the evidence we know and the known behavior of chemicals?

Enjoy

This logical “proof” also explains why all mountains, which we know result from natural processes, are essentially identical chemically. (What? What do you mean their not?) Well then, it does explain why all the planets in the solar system, which we again know to result from natural and well understood natural processes, are essentially chemically identical. (What? You’re telling me that the planets also have a lot of chemical diversity?) Wow, it seems that natural processes produce a great deal of chemical diversity. But that doesn’t apply to life forms. Apparently, the earliest life forms included one type that was somewhat more survivable than all the other forms, and that life form then scattered all over the 200,000,000 square miles of early ocean and ate all the other life forms leaving no trace of their existence.

The only time we see a high level of uniformity in the chemical and morphological makeup of things is when those things are man (intelligent) made.

The only time we see a high level of uniformity in the chemical and morphological makeup of things is when those things are man (intelligent) made.

Gosh I didn't know salt crystals were intelligently made ....

I always thought they were self organizing molecular structures that built themselves according to chemical processes.

OMG -- LOOK at all these signs of intelligence!!!

Enjoy

Edited by RAZD, : .

It seems to me that the natural laws that exist in our universe dictates how the chemistry will work. IOW life is possibly an emergent property of biochemistry.
There are some rather interesting takes on how creatures can extract energy and live. Such as zooxanthellae in corals, tube worms living near geothermal energy etc..
It seems to suggest that living on this particular planet with this particular gravity and in the goldilocks zone from a star is not the only way life can emerge and eventually evolve.
Life it seems will find a way. I heard that in a movie somewhere.

..,.according to chemical processes.

And just who do you think determined those chemical processes?

In the words of the great Ishnar Kalibane: “True enlightenment resides in the process, not the substance.”
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“Seek not to counter those words said in jest, else ye are doomed to eternal impotentcy.”

Does there have to be a who to determine chemical processes?

..,.according to chemical processes. And just who do you think determined those chemical processes?

Deist god/s are one possibility, but not the only one.

... “True enlightenment resides in the process, not the substance.”

Leaping to concussions gives you headaches rather than answers.

Enjoy

"Man who stands on toilet is high on pot"

Deist god/s are one possibility, but not the only one.

Do not underestimate the powers of dentist gods for they alone know the path to the tooth.
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“That which is cannot be otherwise, until it is (otherwise)” Ushnar Kalibane in his The Shnogwhriths” canto 3, verse 7.

Edited by Adminnemooseus, : Fix quote box.

John Sullivan writes: Examples of slightly different genetic codes exist but there are a number of possible explanations for their existence, none of which invoke the agency of the supernatural.

Could you enlighten us on what those possible explanations are?